Coating for flongs



UNITED STATES PATENT OFFICE.

0'1"].0 STBUENSEE, OI PHILADELPHIA, PENNSYLVANIA.

COATING FOB FLONGS.

Patented July 19, 1921.

state, the pulp matrix with its coating afore- 1,385,284 Specification of Letters ratent.

No Drawing. Application filed September 22, 1920. Serial No. 412,021.

To all whom it may concern:

Be it known t at I, Om, Srnunnsaa, a

citizen of the United States, residing in Philadelphia Pennsylvania, have invented Coating for longs, of which the following is a specification.

This invention relates to compositions particularly adapted for coating the surfaces of stereotype matrices, and one object of this invention is to provide a coating of such a nature that it will perfectly fill the pores and enter all depressions,no matter how minute, in the plate to be duplicated when the pulp to which it is applied is properly pressed at ainst it.

It is further desire that the coating shall be of such a nature as to attract rather than repel the molten metal of the casting and to present to the latter a perfectly smooth surface, which permits the fiong being easil freed from said casting when this has su ciently cooled.

Further, the invention contemplates a coating of such a nature as will fit it for use in commercial stereotyping work, so as to make possible the satisfactory reproduction of half tones, in contradistinction to the coarser newspaper work commonly done, and it is also desired that the coating shall be of such a nature as to completely penetrate and as it were, 'amalgamate with the fibers of stereotype paper or pulp in order to impart to it the stren h necessary to prevent its being injured the high temperature of the molten meta to which it is exposed.

In accordance with my invention the con1- position which I have invented consists of a mixture of ten parts air floated talc, two parts of pulverized corn flour, one half part ulverized (gum arabic, one half part of ormaldehy e or any other preservative and about thirty parts of water. After these ingredients are intimately mixed, they are oiled until the liquid has a creamy consistency, when it is allowed to cool.

It may now be applied to the surface of the ulp or pa er constituting a fiong, prior to t e application of the latter to a plate to be dugleicated, either by being brushed on or by ing poured over the surface of said fiong in such manner as to allow the surplus liquid to run all Wh le still in a plastic said is applied to the face of the plate to be duplicated and is dried and otherwise treated in the well known manner for the production of stereotyped molds. Owing to the peculiar composition and nature of my coating, the matrix may be easily freed or removed from the plate after being forced into intimate contact therewith, and when examined under the microscope is found to have perfectly received even the most minute variations'in the surface of said late, so that it is especially adapted for hall tone re reductions.

hen molten metal is poured into the mold prepared as above, I have found that it wets or is attracted to the material of the coating, perfectly entering all the depressions and surface variations of the matrix without injuriously affecting the same, be-

cause said coating penetrates and completely fills the minute spaces between the fibers of the paper, and presents to the molten metal a hard, smooth and unbroken face which gives to the matrix a long life and'permits it to be used for a number of reproductions or castings.

While I preferably use air floated talc as the principal ingredient of my coating compound, other equivalent substances such as china clay or kaolin may be used without departing from my invention, although they do not give as good results since they lack the fine division and "other characteristic qualities of the tale and to a greater or less extent repel molten stereotype metal. Likewise while I preferably use finely pulverized corn flour, it is possible to employ other substances such as rice starch, but again this "does not give as satisfactory results as I have found produced by corn flour. In place of the gum arabic, dextrin or other suitable adhesive material may be employed.

I claim 1. A coating for stereotype matrices containing a finely divided base material having the characteristic of attracti-n molten stereotype metal; a starchy materia an adhesive; with a suspending liquid.

2. A coating for stereotype matrices containing a finely divided base material hav- I ing the characteristic of attracting molten taining approximately twenty parts of' finely divided talc; four parts of corn fiour;. one part of an adhesive; with sixty parts of water.

7. A coating for stereotype matrices containing approximately twenty parts of finely divided talc; four parts of corn flour; one part of an adhesive; sixty parts of water; with one part of formaldehyde.

8. A coating for stereotype matrices consisting of a creamy liquid containing approximately twenty parts of air floated talc; four parts of corn flour; one part of gum arabic and one part of a preservative.

OTTO STRUENSEE. 

